Conventionally fabric is cleaned using water and a detergent composition, which is known as wet cleaning. Surfactants in the detergent adsorb on both fabric and soil and thereby reduce the respective interfacial energies and this facilitates removal of soil from the fabric.
Alternatively it is done by a process called dry cleaning where organic non-polar solvents are used, generally aided by a surfactant. During dry cleaning, when a surfactant is used, a maximum of about 10% of water is also used along with the solvent system in order to facilitate the removal of water soluble stains. In dry cleaning, soil removal can be achieved by a small reduction in interfacial tension. The organic solvent helps in removal of oily soil in the presence of detergents and the particulate soil is largely removed by providing agitation.
Regardless of the type of solvent used, which may be water or an organic solvent, agitation of garments in the cleaning medium is essential to accelerate the removal of soluble soil or insoluble, particulate soil.
U.S. Pat. No. 4,115,061 (Henkel) discloses a method of cleaning using a combination of an organic solvent and a concentrated aqueous detergent solution for cleaning soiled textiles.
U.S. Pat. No. 4,378,968 (Chloe Chimie) discloses a process for reducing soil redeposition onto textiles in order to limit the phenomenon of ‘greying’ of the textiles by incorporating at least one primary or secondary alcohol as an anti redeposition adjuvant into the percholoroethylene solvent during dry cleaning.
GB 1493619, GB 1470332 and GB 1312284 (PPG Industries) disclose a method of treating fabrics in a two-phase liquid comprising a conventional drycleaning liquid as a major portion and a hydrogen peroxide bleaching solution as a minor portion. Typically the peroxide solution is present at less than 10 wt % of the drycleaning liquid (approximately 9 wt % of the two-phase liquid) and preferably less than 5 wt % of the drycleaning fluid (approximately 4.75 wt % of the two-phase liquid).
EP0075546A (Berol Kemi) discloses a water-in-perchloroethylene microemulsion containing 2-6 wt % emulsifier (surfactant) and 0.2-4 wt % solubilising agent included in order to reduce interfacial tensions to stabilise the emulsion thus formed.
WO97/19164A (Colgate-Palmolive) discloses a liquid fabric washing composition in three phases which comprises, among other ingredients, 1 to 15 wt % of non-polar liquid, 55 to 95wt % of a polar solvent, preferably water, and 1 to 23 wt % of a low molecular weight amphiphilic compound. The amphiphilic compound reduces the interfacial tensions to less than 10−3 mN/m to enable a single continuous phase to be formed with minimal mechanical agitation.